Iso-delete Options

charlesvolare

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I'm looking into doing an iso-delete on my volare, firm feel seems a bit more pricey than what I'm wanting to spend. What are other the ways to do this- I remember seeing there's ways to swap shock plates, maybe there's a way to fab up the same thing from firmfeel?
 

Kernel Sanders

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Just find some 8.75 shock plates, tack weld washers in the oversized centering holes.
See the 8.75 shock plates for sale all the time on FABO
you will need different shocks as well
 

NorthernNYMOPAR

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Got tools? Like welder, drill or drill press, saw, steel? Make them, I cut up the plates, welded new centers in, added reinforcements to keep from bending, ordered new longer u-bolts and did it myself, bunch of time, engineering, tools, and you can make it. Part of the reason I did it was to keep the original type shock mounting.
 

charlesvolare

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Got tools? Like welder, drill or drill press, saw, steel? Make them, I cut up the plates, welded new centers in, added reinforcements to keep from bending, ordered new longer u-bolts and did it myself, bunch of time, engineering, tools, and you can make it. Part of the reason I did it was to keep the original type shock mounting.
Yeah I have tools and a welder and everything, in school for engineering so I have confidence I can do it correctly. I want it to appear stockish and be strong. Do you have pictures of your setup?

Just find some 8.75 shock plates, tack weld washers in the oversized centering holes.
See the 8.75 shock plates for sale all the time on FABO
you will need different shocks as well
I have an 8.25, would that just be slightly modifying A body (or is it B body) mounts and clamping it all back together? Are there pictures of this as well?

I'm trying to see what options there are, I need to replace shocks anyways so I'm not to worried about using the same shock setup. I do know performance f-body shocks are somewhat limited. I haven't looked into what shocks are available if I changed the mount but if I could get a cheap set of used mounts with a bigger selection of shocks I'd go with that than stock setup with the smaller selection. Again, I haven't looked into everything, just trying to figure it all out before I make a choice.
 

brotherGood

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B body shock plates, b body shocks, you'll need new u bolts and you'll have to modify the top plate if you have and want to keep the sway bar.

That's where I'm at with mine. Picked up a set of monroe b body shocks for like 25 bucks on amazon.
 

Duke5A

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Firm Feel used to sell the top plates separately. Don't know if they still do and you only need them if you have a sway bar. Bottoms were just your standard B body plate. Think I made a bushing for the centering bolt in the springs, can't remember.

IMG_3227.JPG
IMG_3228.JPG
 

brotherGood

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Firm Feel used to sell the top plates separately. Don't know if they still do and you only need them if you have a sway bar. Bottoms were just your standard B body plate. Think I made a bushing for the centering bolt in the springs, can't remember.

View attachment 33027 View attachment 33028

I forgot you had told me that, I've contacted FirmFeel about this and will forward back the response for others looking to keep the sway bar.

Also, what size ubolts? New ones are a given, but I would imagine new of the same size would come out being too long..is that correct?
 

BudW

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Several issues at play here.

In my opinion, getting rid of the rubber ISO-clamp biscuits is one of the best bang-per buck mods you can make, for it will improve ride many times over.
When new, the rubber might isolate the road to car, just fine, but after a few short years – not so much (and it compounds ride harshness, wheel hop and other issues when the rubber breaks down).

Chrysler has not made new rubber ISO biscuits for a couple decades. Replacing the rubber biscuits with urethane (or polyurethane) is one option. This allows you to use the original hardware. Several members here have gone this way with great success – but I do not prefer it. The lower U-shaped bracket is weak at the bolt holes and I have seen several crack/fail over the years. If this bracket breaks, your car will need a tow truck to get anywhere – for the leaf spring will be dragging ground and the rear wheel will be contacting the inner fender well.
IMG_2456a.JPG

The area in blue circle is where it is weak at (which you can see is bent, in the picture).
Also, if upgrading to 5-leaf springs, the lower U-shaped channel is different (1-leaf taller - see red line) – so one more part to have to locate.


To get rid of the ISO-clamp altogether, you have several options:
One is to use a shock plate made from ‘60ish to mid ’70’s from any A, B, C and E-body with the following exceptions: ’70 E-body plates are made different (1 year only plate) & any 7¼” differential (which has a 2½” tube vs. 3” tube for all other Chrysler differentials). Chrysler started to use the ISO-clamp in the early ‘70’s on a few cars and on most all cars by the mid ‘70’s. The FMJ ISO-clamp is different than the other body style clamp systems are.

If you use an older shock plates – also locate rear shocks for any ’66-79 B-body (which is a more common part than FMJ rear shocks, are).

There are other companies (than Firm Feel) who also makes shock plates and I have seen some new plates around the $60-dollar range. I have purchased used shock plates in that same dollar figure – but most people are asking for about $100 for a pair.
There is nothing wrong with making your own plates – if you have tools and patience to do so. Personally, I’d rather just get a set, ready to go.

The Firm Feel set allows you to use the existing top ISO-plate (to use original shocks) and a different lower plate (not an older style shock plate), so you can toss the rubber and that style works fine, as well.
FFI ISO delete kit.jpg



https://www.ebay.com/itm/Mopar-Dodge-Plymouth-8-3-4-Dana-Shock-Plates-MMR-0178/183559364777?hash=item2abcfda0a9:g:OKYAAOSwWXFb28Ys:rk:44:pf:0
shock plate B.jpg


https://www.ebay.com/itm/Mopar-Dodge-8-3-4-Shock-Plates-Hardware-8-1-4-Dana-60-A-B-C-E-Dart-Duster7-Hemi/132934646022?hash=item1ef385b906:g:vukAAOSw9D1cUNn7:sc:USPSPriorityFlatRateBox!73127!US!-1
shock plate D.jpg

Can still see the OE part numbers on this used pair.

https://www.ebay.com/itm/Dodge-Plymouth-8-3-4-9-3-4-Dana-Rearend-Leaf-Spring-Shock-Mounting-Plates/253971986168?hash=item3b21e8f6f8:g:FuwAAOSw3ydV1IwL:rk:47:pf:0
shock plate E.jpg

This one has U-bolts (by the way – just look for any ABCE-body U-bolds. ’69 is a good year to look up (they are the same for any pre-ISO clamp system). I highly recommend using NEW U-bolts/nuts (Chrysler calls the U-bolts – Clips, for some reason).

Even if reusing the original ISO-clamp – I still highly recommend using NEW U-bolts/nuts (even if you can get them off, intact).

All FMJ differentials have a hole in mounting perch which is (I believe) 1-7/16” in diameter. A person will need to fill that hole with a piece of metal or something to match the bolt on leaf spring (which is typically 1/2” diameter). Some welding might be needed. I have taken some used washered nuts and placed in the hole that make for great spacers – but I do not recall what they came from. Several options here – but you do need something solid to keep the differential centered on springs – or bad things will happen over time.

If a person is replacing an FMJ differential (either 7¼” or 8¼”) with an ’65-70 8¾” version – then shock plates is usually all you need (it fits like a glove, err, a rather tight glove).

One last thing, the Pre-ISO clamp leaf-spring "centering bolt" is slightly different diameter (the head and nut portion) than the post-ISO clamp centering bolt is - so a person can either drill out the shock plate to the wider ISO centering bolt or replace the bolt with older style. Either method works. If you replace the bolt, get two clamps and tighten the leaf spring - on both sides of the centering bolt. Remove and replace the bolt. Loosen and remove your clamps and that job is done (other than purchasing a new pair of odd shaped bolts). I think drilling out the shock plates might be faster/cheaper - but you won't be able to reuse the plates on something else down the road . . .

The second picture down on this post, the FFI kit. The center lower section of that picture – they include new spring center-bolts as well as washers to fill the differential perch holes. Their kit is expensive ($265 US) – but it has all needed parts to get rid of the ISO clamps.

I do not like working on shocks (front or rear) that use the stud/nut design (like FMJ rear shocks lower attachment) – so using a B-body shock is a plus, to me (easier replacement – down the road).
Don’t even get me going about the front FMJ shocks (with the dual stud/nut design).

I hope this helps
BudW
 

brotherGood

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I'll drag this back up (kind of thread jacking, so..sorry)

My question is pertaining to the centering pin. I understand the older style is much smaller (3/8 inch I believe) versus the FMJ perch (1 5/8 inch IIRC)

Since I've not started disassembly yet, I'm curious as to how the center pin and perch interact. More importantly, how they all go together so I can figure out how to address the size difference.
 

volare 77

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I have these for sale. You would need to get the shock studs as they don`t come with them. $95 shipped US.

plates.jpg
 

Duke5A

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That's a good question. All the swaps I've done and seen done involved using an older axle that had perches already on it with the smaller locating holes.

You could make a sleeve with a 1 9/16" outside diameter and hole in the middle so it slides over top of the existing locating pin. This will have to be welded to the pin. I've done this method before.

Your other option is to have different spring pads welded on. You could take the entire axle to rear and end shop and tell them to weld the new perches on at the exact same angle and dimension as the old ones. New perches are only about $30 and the shop labor wouldn't be much. If you can't fabricate then this is your best option.
 

Oldiron440

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I use a 60s Bbody 8 3/4, SS springs and the Bbody shock plates so it all went together like it should.

I will add at one time mopar had SS spring hangers for the Fbody.
 

Duke5A

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I use a 60s Bbody 8 3/4, SS springs and the Bbody shock plates so it all went together like it should.

I will add at one time mopar had SS spring hangers for the Fbody.

I think he wants to retain the factory 8.25" that came in his AHB, so he'll have to figure out what to do with the spring perches. Kind of funny, this is the first time I've ever seen someone doing an ISO-delete while retaining the factory axle.
 

Oldiron440

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I swapped the 8 3/4 on factory springs at first and I welded the hole in the axle pad then drilled the larger hole needed then when going back to the smaller size with the ss springs I welded a flat pad on the axle pad with the correct hole size in it.
 

brotherGood

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I think he wants to retain the factory 8.25" that came in his AHB, so he'll have to figure out what to do with the spring perches. Kind of funny, this is the first time I've ever seen someone doing an ISO-delete while retaining the factory axle.

I've actually got 2 8.25 axles..both are from Ms. One guy on the Facebook group just did a big write up and he had almost like a spacer made...I just dont know how thatd work as far as everything fitting together
 

Duke5A

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Were you planning on taking it to a shop to get looked over or just bolting it in as is?
 

brotherGood

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I've got a buddy who is a Chrysler mechanic who will be rebuilding it for me. I would imagine he could weld new perches, but im trying to see how I can avoid that
 
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